Field of the Invention
This disclosure relates generally to brake force sensor arrangements and, more particularly, to a brake force sensor arrangement for a brake unit of a railway vehicle.
Description of Related Art
Federal regulations for the inspection of brake units on railway vehicles now mandate that each commuter and short-distance intercity passenger train shall receive a Class I brake test at least once during each calendar day that the train is placed or continues in service. Therefore, transit authorities manually inspect the brake systems on passenger trains on a periodic basis to ensure they are working properly. Operators must apply pressurized fluid to the braking system and ensure that the brake pads on the calipers of the disc brake units or the brake shoe of the tread brake units properly contact the disc surface or treads of the wheels of the railway vehicle. Train operators must walk the length of the train and visually verify pad-to-disc or shoe-to-tread contact. During these inspections, it is often difficult for the operator to see and properly identify brake application, especially on cars in which the brake units are located in-board of the railway vehicle. When the brake units are positioned in-board of the railway vehicle, it is often necessary for the operator to inspect the brake units using a pit or maintenance facility to gain access to the in-board portion of the railway vehicle. Further, the inspection of the brake units is very time consuming.
The proper function of the brake units can be checked by monitoring air pressure or piston travel of the brake units, but these methods are not always reliable. Occasionally, air pressure or piston travel is present but no force is being applied to the brakes, such as if the brake unit is jammed or the brake shoe/pads are missing. Ultimately, measuring the brake force of the brake unit directly is the best way to verify that the brakes are working properly.
In view of the foregoing, a need exists for a brake force sensor arrangement that eliminates the need for periodic manual inspection of the brake system on railway vehicles. A further need exists for a brake force sensor arrangement that provides an individual with additional information about the performance of the brake system and that aids in identifying brake units that are not functioning properly.